抗原致敏树突细胞激活细胞毒性T淋巴细胞的体外抗肿瘤作用

目的 利用新型诱导剂钙离子载体(CI)A23187联合重组人粒细胞-巨噬细胞集落刺激因子(rhGM-CSF)体外诱导人外周血单核细胞(PBMC)生成树突细胞(DC),观察DC刺激细胞毒性T细胞(CTL)对人白血病细胞K562细胞产生的特异性杀伤作用.方法 采用密度梯度离心法及黏附法分离出PBMC,分2组培养:传统方法组,加人rhGM-CSF+重组人白细胞介素4+重组人肿瘤坏死因子-α;新型诱导剂组,加入rhGM-CSF+CI A23187.培养开始前,予K562细胞冻融抗原致敏,培养96 h后收集负载抗原的DC.光镜观察细胞形态的变化;流式细胞仪检测DC细胞的表面标志;四甲基偶氮唑盐比色法检测各组DC刺激同种异体外周血T细胞增殖的能力、DC对K562细胞的抑制作用和DC激活的CTL细胞对K562细胞的杀伤作用.结果 与传统方法相比,A23187联合rhGM-CSF 诱导培养的DC具有更加典型的树突形态;DC 表面分子CD83、CD1a、CD86、CD40表达(45.2%±1.8%、31.5%±3.9%、40.1%±7.8%、36.4%±6.3%)较传统方法组(16.9%±1.3%、20.4%±3.4%、26.5%±2.2%、22.3%±3.0%)明显高(均P<0.05),且CD14表达(5.7%±0.8%比19.0%±1.6%)明显低(P<0.05);负载K562细胞冻融抗原后的DC具有明显刺激同种异体T细胞增殖作用;对K562细胞有明显抑制作用,效靶比为1:1及10:1时,抑瘤率分别为(25.3±3.8)%比(15.6±2.4)%、(35.6±5.2)%比(22.9±3.2)%(均P<0.05);刺激的CTL对K562细胞有明显的杀伤作用,效靶比为10:1及40:1时,杀瘤率分别为(44.3±6.2)%比(29.9±2.8)%、(61.0±5.2)%比(43.1±4.8)%(均P<0.05).结论 新型诱导剂CI A23187联合rhGM-CSF能更有效地诱导PBMC生成强效成熟DC,K562细胞冻融抗原冲击该DC激活CTL能够获得较强的杀伤K562细胞的能力.

In vitro anti-tumor effect of cytotoxic T lymphocyte activated by antigen- loaded dendritic cells from peripheral blood mononuclear cells treated with calcium ionophore A23187 and GM-CSF

Objective To evaluate the effect of calcium ionophore (CI) A23187 and human recombinant granulocyte/macrophage colony stimulating factor (rhGM-CSF) on the cultivation of dendritic cell (DC) from healthy human peripheral blood mononuclear cell (PBMC) and to evaluate the in vitro effect of DC stimulated by K562 cell lysate on inducing specific cytotoxic T lymphocyte ( CTL) against K562 cell Methods Human PBMCs isolated from healthy subjects were separated into two groups. In Group A,the cells were cultured with additional rhGM-CSF, recombinant human interleukin 4 and recombinant human tumor necrosis factor-a only as control group. In Group B, the cells were cultured in the presence of rhGMCSF and CI A23187. The cells in both groups were pre-incubated with K562 cell lysate at 37℃for 30 min.The cells were harvested after a 4-day cultivation. Morphology of DC was continuously observed under inverted microscope. The surface antigens of induced cells were analyzed by flow cytometry (FCM). Then the proliferation of allogenetic T cell and the specific cytotoxicity of T cell primed with DC were examined by colorimetry. Also, the nonspecific inhibition of DC loaded K562 cell lysate against K562 cell was detected.Results Typical morphological features of DC could be observed in both groups. The expressions of CD83,CD1a, CD86 and CD40 were stronger in Group B than those in control group (45. 2% ±1.8%, 31.5% ± 3.9%,40.1%±7.8%,36.4%±6.3% vs 16.9%±1.3%,20.4%±3.4%,26.5%±2.2%,22.3%±3.0%)(all P<0.05).The expression of CD14 Was weaker in Group B than that in control group (5.7%±0.8% vs 19.0%±1.6%)(P<0.05).As compared with the control group,DC in Group B loaded with K562 lysate could evidently stimulate the Proliferation of allogenetic T cell(P<0.05.exclusion of effector-to-target ratio of 1:40)and inhibit the growth of K562 cell(P<0.05).In addition.both groups of DC-stimulated CTL had specific cytotoxicity against K562 cell.At the effector-to-target ratios of 10:1 and 40:1.the DC-stimulated CTL of Group B had stronger cytotoxicitiy against K562 cell(both P<0.05).Conclusion In combination with rhGM-CSF.CI A23187 induces PBMC into DC in a more effective way.DC loaded with K562 lysate can stimulate CTL and maintain high immunocompetence with specific cytotoxicity against K562 cell.